1. Field of the Invention
The present invention relates to an ophthalmologic photographing apparatus that is used in an ophthalmic hospital, and its photographing method.
2. Description of the Related Art
A fundus camera that photographs a fundus of a subject's eye has widely been known as an ophthalmologic photographing apparatus. The fundus camera can photograph a fundus using a plurality of photographing methods (“photographing method” is sometimes referred to as “photographing mode” hereinafter) which include infrared fluorescent photography and visible fluorescent photography. In this case, a user sometimes changes a light emission amount of a light source during the photography. Japanese Patent Application Laid-Open No. 2002-200047 discusses a technique in which the light emission amounts for the plurality of photographing methods are recorded, and the photographing is started with the recorded light emission amount in the next photographing.
In the case of fundus autofluorescence photography (the photography in which lipofuscin that is a waste product on retinal pigment epithelium is excited without using a fluorescent agent), it has been found by the applicant of the present invention that individual differences of the excited light in age, race, or sex are small. The applicant of the present invention has also found that, when a subject's eye having a lesion such as a cataract is photographed with fundus autofluorescence, the light emission amount of the light source has to be lowered. A light-transmitting part is opacified in the cataract. Therefore, when the subject's eye having the cataract is photographed with an ordinary light emission amount, a light scatter at the opacified part might affect imaging of the lesion.
It is considered the case in which a subject changes the light emission amount in Japanese Patent Application Laid-Open No. 2002-200047. In this application, the light emission amount that is changed for photographing a subject before the change is also applied to a subject after the change, even if the subject after the change is photographed. In this case, when the subject's eye has a cataract or other lesion, the light emission amount (initial value) at the start of the photography has to be reset to a fixed value (a light emission amount that is set beforehand as an initial state of the light source), so that an operation load to a user may increase.